The present invention relates to an anti-rotation device for a fastener. Specifically, the present invention relates to a device that limits the rotation of a fastener when tightening or loosening the corresponding fastener.
A gas turbine engine has several modules. The first module, in terms of axial flow path, is the compressor section. Ambient air enters the engine through the compressor section. The compressor section pressurizes the air.
The second module is the combustion section. The combustion section introduces fuel to the air previously compressed by the compressor section. The combustion section then ignites the mixture.
The third module is the turbine section. The turbine section extracts energy from the exhaust produce by the compressor section. The turbine section is coupled to the compressor section so that the exhaust drives the compressor.
Finally, the air exits the engine as thrust.
FIG. 1 is a perspective view of part of a gas turbine engine 10. The drawing shows a first module, such as a compressor section 11, adjacent a second module, such as a combustion section 13. The cases of these sections 11, 13 have corresponding flanges 15, 17 which abut and define a joint 19.
Fasteners, such as 12-point bolts 21 and nuts 23, extend through aligned openings in the flanges 15, 17 to seal the joint 19. FIG. 1 displays the conventional method of tightening the bolts 21 and nuts 23. The typical method requires the operator first to manipulate both a manual wrench W and a pneumatic impact wrench I. The manual wrench W engages the nut 23 and the pneumatic wrench I engages the bolt 21. After actuating the impact wrench I, the operator prevents rotation of the nut 23 by applying torque to the wrench W. As the bolt 21 and nut 23 tighten, the operator must apply an increasing amount of torque to the wrench W. The operator replaces the impact wrench I with another manual wrench W to provide the final torque to the fasteners. Now, the operator must apply torque to both manual wrenches W.
Loosening the bolts 21 and nuts 23 is similar. The operator engages the nut 23 with the wrench W and the bolt 21 with the second manual wrench W. The operator applies torque to both manual wrenches to loosen the fasteners slightly. Then operator then replaces the second manual wrench W with the impact wrench I. The operator then actuates the impact wrench I to remove the loosened bolt 21. The operator applies the greatest amount of torque to the wrench W during initial loosening of the fasteners. As the bolt 21 and the nut 23 loosen further, the operator can apply a decreasing amount of torque to the wrench W.
The operator must apply a typical torque of between approximately 30 and approximately 1000 in-lbs. Since the joint 19 may have up to 160 pairs of bolts 21 and nuts 23, the possibility of operator fatigue does exist. Since the engine 10 may have at least four joints 19, the possibility of fatigue becomes even more apparent.
It is an object of the present invention to provide a new and improved anti-rotation device.
It is a further object of the present invention to provide an ergonomically beneficial antirotation device.
It is a further object of the present invention to provide an anti-rotation device that reduces operator fatigue.
It is a further object of the present invention to provide an anti-rotation device that does not require the application of torque by the operator.
It is a further object of the present invention to provide an anti-rotation device that allows the operator to tighten or loosen a pair of fasteners with only one hand.
It is a further object of the present invention to provide an anti-rotation device that increases the speed that an operator can assemble or disassemble an assembly secured together by multiple fasteners.
These and other objects of the present invention are achieved in one aspect by an antirotation device for a fastener. The fastener comprises: a first coupling for engaging a first fastener; a second coupling for engaging a feature located near the first fastener; and a flexible connection between the first and second couplings. The flexible connection limits the rotation of the first coupling relative to the second coupling.
These and other objects of the present invention are achieved in another aspect by kit for preventing rotation of a fastener. The kit includes an anti-rotation device and a holder. The antirotation device includes a first coupling for engaging a first fastener; and a second coupling for engaging a second fastener located a distance from the first fastener. The second coupling is flexibly connected to the first coupling. The holder includes: a first opening for receiving the first coupling and a second opening for receiving the second coupling. The spacing between the first and second openings corresponds to the distance between the first fastener and the second fastener. The second coupling limits rotation of the first coupling.
These and other objects of the present invention are achieved in another aspect by a method of preventing rotation of a fastener. The method comprises the steps of: placing a first coupling on a first fastener; placing a second coupling on a feature located near the first fastener; flexibly connecting the first and second couplings; tightening or loosening a third fastener corresponding to the first fastener; and limiting rotation of the first coupling while tightening or loosening the third fastener.